1. Field of the Invention.
This invention relates to improved hardenable resin compositions and methods, and more particularly, to such compositions and methods wherein less hazardous and more compatible hardening agents are utilized.
2. Description of the Prior Art.
Resin compositions useful for consolidating particulate materials into hard permeable masses have been developed and used heretofore. In the oil industry, resin compositions and methods for placing particulate materials coated therewith are used, for example, to form hard permeable masses in subterranean formations containing loose or incompetent sands which migrate with hydrocarbons produced therefrom. The hard permeable masses formed by the consolidated particulate materials reduce or prevent the migration of loose or incompetent sands when placed between the producing formations and the well bores penetrating the formations.
One technique which has heretofore been utilized successfully for forming a consolidated, permeable, particulate mass between a well bore and a producing formation involves coating the formation sand adjacent the well bore with a hardenable resin and then causing the resin to harden. An alternate technique has been to coat sand with a hardenable resin on the surface, to suspend the coated sand in a gelled aqueous carrier liquid and then to pump the suspension by way of the well bore into the formation whereby the resin coated sand is deposited therein. The resin on the deposited sand is caused to harden whereby a solid, permeable, particulate mass is formed.
Methods of continuously forming and suspending consolidatible resin composition coated particulate material in a gelled aqueous carrier liquid and transporting the coated particulate material by way of the gelled aqueous carrier liquid to a zone in which it is consolidated are described in U.S. Pat. No. 4,829,100 issued May 9, 1989. In accordance with such methods, substantially continuous streams of a gelled aqueous carrier liquid, uncoated particulate material, a resin composition which will subsequently harden and a surface active agent are admixed whereby the particulate material is continuously coated with resin composition and suspended in the gelled aqueous carrier liquid.
While the methods and compositions disclosed in Patent No. 4,829,100 have been used successfully, the preferred hardening agents, i.e., hardening agents including methylene dianiline have been found to be carcinogenic and therefore hazardous to personnel, and to be incompatible with some other commonly used components in gelled aqueous fluids such as oxidative gel breakers and the like. Aliphatic amines have been utilized and are well known to those skilled in the art as hardening agents for epoxy resins. However, because such amines are either soluble in or form emulsions with water, they tend to separate from the resin composition while the resin composition is being mixed or placed, and as a result, they often do not satisfactorily cause the resin composition to harden.
Thus, there is a need for an improved hardenable resin composition which is less hazardous to personnel, which is compatible with other components utilized in subterranean formation treating fluids and which causes the resin composition to rapidly harden and develop high strength in the presence of water.